1. Field of the Invention
The present invention relates to a hydraulic excavator provided with a dozer device.
2. Description of the Related Art
Normally, a dozer device provided on a lower traveling body of an excavator carries out a work with its dozer blade placed in contact with the ground. It is also used in case where the dozer blade is pressed against the ground to levitate either forward and backward direction of the lower traveling body to keep an attitude of the excavator on a slope horizontal (for example, Japanese Patent Application Laid-Open No. 2002-322668).
An approach angle of the dozer blade as a climbing angle from the ground is determined so as not to be caught by the ground when climbing a bridge spread between a loading platform of a truck and the ground, and more specifically, the angle is set to approximately 28 degrees. The approach angle is an angle between the ground and a plane in contact, in a tangential direction, with a front circumferential surface of a crawler shoe passing through a lower end of the blade when the blade is raised to an upper limit position.
However, the excavator has a high value that can adjust a leveling work and the attitude of the machine body, whereas has a disadvantage caused by being provided with the dozer device.
For example, it cannot climb over a stacked hill without digging it up as in an excavator not provided with the dozer blade. Further, when traveling along a readjusted slope, the slope is sometimes dug up by the dozer blade.
Furthermore, when climbing on the loading platform of the truck, attention should be paid so as to prevent the dozer blade from being caught by the ground.